1. Field of the Invention
This invention relates to an operational control unit for a fuel cell system including a fuel processor and a fuel cell, and more particularly to an operational shut-down device for the fuel cell system.
2. Description of Related Art
Recently, it has been proposed to provide a compact power supply offering a ready source of electrical energy that may be utilized for a wide variety of purposes. For example, such compact power supplies can be employed for providing electrical power for campsites, small watercraft not having their own power systems, and a wide variety of other purposes. A power supply of this type may include an electrical generator that is driven by a small internal combustion engine, such as a single cylinder, two-cycle, crankcase compression engine. For safety and other purposes, it is desirable if the engine can be powered by a gaseous fuel of the type that is stored under pressure in a container. Such fuel sources are readily available.
Such fuel cell systems are generally equipped with a fuel processor to generate the fuel gas. The fuel processor, along with the fuel cell, is operationally controlled by a control unit.
Conventionally, when the operation of this type of fuel cell system is to be halted while turning off the external load through a main switch, the power to the control unit must be separately turned off. Turning off the control unit at this time has several disadvantages, however. First, if the fuel processor's combustion burner is not stopped at the time operation of the cell is stopped, the burner in the fuel processor continues to burn until operations are resumed, thus wastefully consuming fuel. Also, when the system is a hybrid of the type including both fuel cells and storage batteries, then at the time operations are halted, the charge level for the storage batteries may fall below the rated value, which can impair the smooth restarting of operations.
Accordingly, when such conventional fuel cell systems are shut down, operations supervisors must pay close attention to the above factors, and only then shut down power to the controller.